Red Flags Optical Illusion

Are these two objects the same size?

In this optical illusion, the two objects look like waving flags. They are lined up as if they were both attached to the same flag pole. The shading makes them look like they are waving in the wind. If they were flags, they would be rectangular so we assume they are.

In sizing them, we compare the bottom right corner of the upper “flag” with the top right corner of the lower “flag.” Since we think they are rectangular, the top one looks smaller.